Drawbench tongs



July 2v8, 1931. v E. K. HoLMEs 51,816,484

DRAWBENCH 'rosas Filed May 24, 1926` HI: l

n u@ LW Patented vJuly 2s, 1931 I1,81fi,484

PATENT OFFICE EARL x. HOLMES, or CLEVELAND, omo,

STEEL AND TUBES, INC., oF CLEVELAND,

ASSIGNOR, BY MESNE. ASSIGNMENTS, T0

OHIO, A CORPORATION OF OHIO DRAWBENCH.' TON GS Application led May 24,

This invention relates to draw benches such as are used in the manufacture of plpes, tubes, bars, rods and the like, and more particularly to the means which engage the end of the article being drawn and the cham or similar member which draws this piece through the forming dies.

An object of the invention is to provide gripping means for drawing an article through a die, which means W111 gr1p the article firmly while it is being drawn, and will automatically release the same when the drawing operation is completed.

Another object is to provide gripping means which will be automatically released from the chain or the like by which it is drawn along the draw bench. L

Another object .is to provide means which will prevent the gripping means from overrunning the end of the bench.

Another object is to provide means for automatically returning the 'gripping means to the end ofthe bed at which it recelves the article to be drawn. A I

Other objects will hereinafter appear.

...The invention will be better understood from the description of one practical embodiment thereof for drawing pipe, illustrated in the accompanying drawings, in which- 1 Fig. 1- is a plan view of a carriage pro- .vided with pipe gripping means and chain engaging means; K.

Fig. 2 is a side elevation of the device shown in Fig. 1'; and

Fig. 3 is a side elevation of a showlng the partsillustrated in Figs. 1 and 2 inoperative relation thereto and in the position they occupy at thestart 'of a drawing operation.

Referring first to Fig. 3, the draw bench consists of a top 1 supported on legs 2. At the end of the bench, which is shown to the right in the drawings, dies 3'are provided through' which the pipe is drawn. A chain 4 is provided which moves along the top of the bench to the left as shown in Fig. 3.

carriage, indicated generally'at 5, moves draw bench,

1926. Serial No. 111,274.

for engaging the chain so that the carriage and article maybe drawn along the bench. These Ineans will be more particularly described in connection with Figs. 1 and 2. The carriage has attached thereto a cable 6 which runs over sheaves 7 and carries at its end a weight 8 which returns the carriage to the position shown in F ig. 3 is released from the chain. The table is also provided at the end shown to the left, and hereinafter called the rear end, with a plate or the like 9 adapted to be engaged by a part of the carriage to release the same from the chain, providing the chain has drawn it to-the extreme end of the table.

he carriage comprises two 'horizontal members 10 and 12 each provided with two wheels upon which the carriage moves along the top of the bench.- The upper frame member 10 carries rigidly a vertical post or Apin 11 at its forward end which extends both 14 thus moving the frame members 10 and whenever it.

12 longitudinallywith respect to each other i and thereby movlng the axes 16 and 17 on which the wheels 18 are mounted toward and from each other to a limited extent. On the rear end of frame member 12 is pivoted a hook 19 for` engaging the chain 4.

Extending upwardly from the rear end ofl frame member 12 is a post 20 and between the upper end of the post and the outer end of the hookl a spring 21 is provided which tends to raise the hook with the chain. The hook has secured vto its outer end a metal strap -22 bent to provide an inclined face 23 for contacting plate 9 to cam the hook up and thus disengage it from the chain whenthe carriage reaches the extreme rear end of the drawbench.

Two levers 24 and 25 are positioned between the frame membgrs 10 and 12 and pivotedl on post 11. The forward end of out of engagement these levers are provided with jaws 24a! and 25a for gripping the pipe end. The levers cross, as most clearly indicated in Fig. 1, and the rear ends of the levers are connected by links 26 and 27, respectively, to post 13, the levers and links forming toggles controlled by relative movement vof posts 11 and 12. A tension spring 28 connects posts 11 and 20 above the upper frame member.

The operation of the device is as follows: With the carriage in the position shown in Fig. 3, the end of the pipe is placed between jaws 24a and 25a, and hook 19 is engaged with a cross-roller ofchain 4 which is moved toward the rear end of the bench. Due 'to the high tension the chain tends to assume a straight line from the pivot'of the hook to the end of the 'bench and therefore pulls up ofi' the bench, as shown at 4. The motion of the chain draws frame member 12 to the left in respect to member 10,-separating posts 11 and 13 and thus causing the toggles, formed by links 26 and 27 and levers 24 a'nd 25, to close the jaws tightly upon the end of the pipe, and also placing the spring28 under tension. The pressure between the chain link andv hook prevents spring 21 from disengaging these. The carriage is drawn along thebench by the chain and draws the pipe through the die 3. When the rear end of the pipe passes through the die, even with the. ordinary K type of carriage, the pipe and carriage leap along the bed, due to the release of tension 35 created during the drawing operation. With the carriage above described this action is increased, as when the resistance to the forward motion of the carriage is very materially decreased the spring 28 contracts, throwing the upper frame member toward the rear end of the bench.7 This expands the toggles which open the jaws, releasing the pipe. The momentum of the upper frame member and parts carried thereby carries them rearward, drivin the lower frame member and partscarriecgl by it rearward. Even with the prior types of carriage the leaping motion of the carriage was suiicient to relieve the pressure between hook 19 and the chain, .and thus allowing spring 21 to disengage the hook from the chain and releasing the carriage, and, as above stated, this motion is increased by the spring and renders the release more certain. The weight 8 is then free to return the carriage to lts starting position. Should the carriage fail to release itself from the chain, it will be carried along therewith until inclinedsurface 2 3 engages plate 9 at which time the hook will be released from the chain and the carriage returned by the weight, as above described.

As the carriage is automatically returned the operator, whose duty it was to return 55 the carriage, may now be dispensed with and the apparatus operated by one man whereas two have always been required heretofore. The production of the one operator is substantially the same as that of two with prior devices and the reduction in labor cost is therefore veryy material. l

While I have described one embodiment of my invention in some particularity, obviously many other variations and modications thereof will occur to those skilled in the art and I do not, therefore, limit myself to the precise details herein described but claim as my invention all such variations and modifications falling within the scope of the subjoined claims.

What I claim is: r

1. A draw bench carriage comprising two relatively movable sections each provided with a pair of wheels, means connecting the sections for relative movement includingrigid members carried respectively by the sections and each member having a lost motion connection with the other section, a pair of gripping jaws pivoted on one of said sections, a pair'of links pivoted on the other of said sections and to said jaws, and resilient means connecting said sections.

. 2. A draw bench carriage comprising two relatively movable sections each provided with a pair of wheels, means connecting the sections for relative movement including rigid members carried respectively by the sections and each member having a lost motion connection with the other section, two oppositely disposed toggles each provided with one of a, pair of gripping jaws and pivotedto each section, resilient means between said sections for normally maintaining them in one relative position, and engaging means carried by one of the sections for engaging a traction chain.

3. A draw bench carria e comprisin a frame composed of two re atively mova le members, a pivot pin carried by each member'and projecting through an elongated slot in the other, and two oppositely disposed toggles pivoted on said pivot pins and extending beyond one of them to form a pair of gripping jaws.

4:. A draw bench carriage frame members each provided with a pair of wheels, a pivot post xed to each frame member and projecting through a longitudinal slot in the other, two oppositely disposed toggles between the frame members 120 and pivoted to said posts, the toggles extending beyond one of said posts and formr inga pair of gripping jaws, and resilient means between the members maintaining the posts normally at respectively opposite 125 ends of the slots.

5. A draw bench carriage comprising upper and lower relatively movable members each provided with a pivot pin xed thereto and movable in a longitudinal slot in the 13o comprising tw 0 115 other, two levers pivoted to one pin intermediate their ends, two links4 ivoted to the other pin at their ends, the en s of the links and levers being pivoted together, and a spring connecting the frame members.

6. A draw bench carriage comprisin relatively movable upper and lower rame members each provided with a, pair of wheels, a downwardly extending pivot post fixed'to the upper frame member and projecting through a longitudinal slot in the lower, an upwardly extending pivot post fixed to the lower frame member and eX- tending through a longitudinal slot in the upper, two' levers pivoted to the downwardly extending post intermediatetheir vends and two links pivoted to the upwardly extending post at one end, the -other end of the first .link being pivoted to the longer vend of one lever and the other end of the second link to the longer end' of the other lever, a chain engaging liookpivoted to the lower frame member, a spring between the hook and' lower frame member urging the hook upwardly and a spring between the upper and lower frame members urging the' frame members tov` 1rd each other.

In testimony whereof I hereunto alix my signature this 20th day of May, 1926.

EARL K. HOLMES, 

